Many decades after the publication of Genesis and development of a scientific fact, Fleck’s collective Denkstil remains a very important notion for analyzing the history of the biological and medical sciences. Following Fleck’s perspective this paper argues that the history of the sex hormones was critically shaped by our representation of the sexes, and our perceptions of the division of reproductive labor. Emerging at the boundary between physiological laboratories and consultation room, a molecular/endocrine style of thought stabilized during the early decades of the twentieth century around the manipulation of sex hormones. This not only proved important in normalizing the sexual body, but also in defining sterility, menstrual disorders or menopause as pathological events to be treated ‘causally’.Analyzing the role played by industrial companies like the German firm Schering which produced these drugs, the paper suggests that the idea of a work style may be a convenient way to complement Fleck’s style of thought. First, the idea of work style is a reminder that science involves material action, which has strong links with industrial production. Second, it draws our attention to a deeply entrenched goal of the modern biosciences, the search for means to control the variability of the living, and standardize its uses